Companies and advocacy groups opposed to the FBI's plan to make the Internet more accommodating to covert law enforcement surveillance are sharpening a new argument against the controversial proposal: that law enforcement's Internet spying capabilities are just fine as it is.

In comments filed with the FCC Tuesday, advocates with the Center for Democracy and Technology argue the government hasn't offered any evidence that law enforcement agencies face obstacles in conducting Internet wiretaps under current regulations -- which obligate ISPs and other companies to cooperate with court-authorized surveillance, but do not force them to retrofit their networks with special surveillance gear, as the government is asking.

"In the absence of evidence of any problem, it is impossible for the Commission to act," wrote CDT, representing a handful of technology companies, industry associations and advocacy groups, including the Computer and Communications Industry Association, Dialpad Communications, the Electronic Frontier Foundation, the Information Technology Association of America, and others.